Stanford researchers presented preliminary findings from a virtual
study that enrolled more than 400,000 participants.

PALO ALTO, Calif.–(BUSINESS WIRE)– Researchers from the Stanford University School of Medicine today
presented preliminary results of the Apple Heart Study, an unprecedented
virtual study with over 400,000 enrolled participants. The researchers
reported that wearable technology can safely identify heart rate
irregularities that subsequent testing confirmed to be atrial
fibrillation, a leading cause of stroke and hospitalization in the
United States.

The study was launched with sponsorship by Apple, Inc., in November 2017
to determine whether a mobile app that uses data from a heart-rate pulse
sensor on the Apple Watch can identify atrial fibrillation. The
condition often remains hidden because many people don’t experience
symptoms.

Key findings from the study include:

Overall, only 0.5 percent of participants received irregular pulse
notifications, an important finding given concerns about potential
over-notification.

Comparisons between irregular pulse-detection on Apple Watch and
simultaneous electrocardiography (ECG) patch recordings showed the
pulse detection algorithm (indicating a positive tachogram reading)
has a 71 percent positive predictive value. Eighty-four percent of the
time, participants who received irregular pulse notifications were
found to be in atrial fibrillation at the time of the notification.

One-third (34 percent) of the participants who received irregular
pulse notifications and followed up by using an ECG patch over a week
later were found to have atrial fibrillation. Since atrial
fibrillation is an intermittent condition, it’s not surprising for it
to go undetected in subsequent ECG patch monitoring.

Fifty-seven percent of those who received irregular pulse
notifications sought medical attention.

“The results of the Apple Heart Study highlight the potential role that
innovative digital technology can play in creating more predictive and
preventive health care,” said Lloyd Minor, MD, Dean of the Stanford
School of Medicine. “Atrial fibrillation is just the beginning, as this
study opens the door to further research into wearable technologies and
how they might be used to prevent disease before it strikes – a key goal
of Precision Health.”

For the study, each participant was required to have an Apple Watch
(series 1, 2 or 3) and an iPhone. The most recent Apple Watch, which
features a built-in ECG, wasn’t part of the study, as it was released
after the study’s launch. The Apple Heart Study app intermittently
checked the heart-rate pulse sensor for measurements of an irregular
pulse. If an irregular pulse was detected, the participant received a
notification and was asked to schedule a telemedicine consultation with
a doctor involved in the study through American Well. Participants were
then sent ambulatory ECG patches through BioTelemetry, which recorded
the electrical rhythm of their hearts for up to a week.

“The study’s findings have the potential to help patients and clinicians
understand how devices like the Apple Watch can play a role in detecting
conditions such as atrial fibrillation, a deadly and often undiagnosed
disease,” said Turakhia. “The virtual design of this study also provides
a strong foundation upon which future research can be conducted to
explore the health implications of wearable technology.”

“The performance and accuracy we observed in this study provides
important information as we seek to understand the potential impact of
wearable technology on the health system,” said Perez. “Further research
will help people make more informed health decisions.”

Researchers from the Lankenau Heart Institute, Jefferson Medical
College, the University of Colorado School of Medicine, Cooper Medical
School of Rowan University, StopAfib.org, the American Foundation for
Women’s Health, and Duke University also contributed to the study.

The Apple Heart Study was funded by Apple, Inc.

About Atrial Fibrillation

Each year in the United States, atrial fibrillation results in 130,000
deaths and 750,000 hospitalizations, according to the Centers for
Disease Control and Prevention. The CDC estimates that the condition
affects between 2.7 million and 6.1 million people. In addition, another
700,000 people may have undiagnosed atrial fibrillation.

About Stanford Medicine

A leader in the biomedical revolution, Stanford Medicine has a long
tradition of leadership in pioneering research, creative teaching
protocols, and effective clinical therapies. Our close proximity to the
resources of the university – including the Schools of Business, Law,
Humanities and Sciences, and Engineering – our seamless relationship
with our affiliated adult and children’s hospitals, and our ongoing
associations with the entrepreneurial endeavors of Silicon Valley, make
us uniquely positioned to accelerate the pace at which new knowledge is
translated into tangible health benefits.